What characteristic distinguishes a logic valve in pneumatic circuits?

A logic valve in pneumatic circuits is specifically designed to perform logical functions by utilizing pneumatic signals rather than electrical signals. This characteristic is crucial because it allows for the manipulation and control of air flow based on certain conditions, similar to how an electrical logic gate operates with electrical inputs.

These valves can combine multiple input signals to produce specific outputs, enabling complex control schemes within a pneumatic system. For example, a logic valve might take two pneumatic input signals and determine an output based on conditions such as both inputs being "on" or one input being "on" while the other is "off."

Other characteristics mentioned, such as operating only with electrical signals or controlling temperature, do not apply to logic valves, which focus entirely on pneumatic logic functions. Additionally, while logic valves can be significant in size depending on their design and purpose, they are not characterized by their size compared to other components in the system. Thus, the key differentiating characteristic of a logic valve is its function of handling pneumatic signals to perform logical operations.